You have to make it clear - verbally.
How else is the girl supposed to know how you feel?
Girls aren't mind readers and neither are guys.
A girl can't assum that she and he are excluse if they both haven't agreed to be exclusive. And guy can't assume that she's his gf just because she ****ed him a few times and they've been hanging out for a couple of months.
A girl will expect you to tell her what you both are doing. They'll even say it, "Hunny, what are we doing? what would you call what we are doing?"
They want to know...
Of the 2 long-term gf's I've been with, I told each of them what I wanted out of the relationship when I was ready and I could tell that they were ready.
I said, "I am not seeing anyone else and I don't want to see anyone else and I hope you're not seeing anyone else (I knew they weren't). I want us to be exclusive with each other."
Both girls went crazy with excitement.
Communication is key for a healthy relationship. Both people should feel comfortable as to "what they're doing" (meaning: are they friends? b/f & g/f? fvck buddies? and so on..)
Girls think that their relationship is good if you both talk about it. They think something is wrong if you aren't talking about it.
It's not about being "in control" of shyt. It's about being happy together and feeling secure.
LTRs are a different situation that being a PU artist or being a DJ looking to mack on a different girl every nite.